/*
***********************************************************************
** md5.c -- the source code for MD5 routines                         **
** RSA Data Security, Inc. MD5 Message-Digest Algorithm              **
** Created: 2/17/90 RLR                                              **
** Revised: 1/91 SRD,AJ,BSK,JT Reference C Version                   **
** Revised (for MD5): RLR 4/27/91                                    **
**   -- G modified to have y&~z instead of y&z                       **
**   -- FF, GG, HH modified to add in last register done             **
**   -- Access pattern: round 2 works mod 5, round 3 works mod 3     **
**   -- distinct additive constant for each step                     **
**   -- round 4 added, working mod 7                                 **
***********************************************************************
*/

/*
***********************************************************************
** Copyright (C) 1990, RSA Data Security, Inc. All rights reserved.  **
**                                                                   **
** License to copy and use this software is granted provided that    **
** it is identified as the "RSA Data Security, Inc. MD5 Message-     **
** Digest Algorithm" in all material mentioning or referencing this  **
** software or this function.                                        **
**                                                                   **
** License is also granted to make and use derivative works          **
** provided that such works are identified as "derived from the RSA  **
** Data Security, Inc. MD5 Message-Digest Algorithm" in all          **
** material mentioning or referencing the derived work.              **
**                                                                   **
** RSA Data Security, Inc. makes no representations concerning       **
** either the merchantability of this software or the suitability    **
** of this software for any particular purpose.  It is provided "as  **
** is" without express or implied warranty of any kind.              **
**                                                                   **
** These notices must be retained in any copies of any part of this  **
** documentation and/or software.                                    **
***********************************************************************
*/

#include "md5.h"

/*
***********************************************************************
**  Message-digest routines:                                         **
**  To form the message digest for a message M                       **
**    (1) Initialize a context buffer mdContext using MD5Init        **
**    (2) Call MD5Update on mdContext and M                          **
**    (3) Call MD5Final on mdContext                                 **
**  The message digest is now in mdContext->digest[0...15]           **
***********************************************************************
*/

/* forward declaration */
static void Transform (UINT4 *, UINT4 *);

#ifdef	__STDC__
static const
#else
static
#endif
unsigned char PADDING[64] = {
	0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};

/* F, G, H and I are basic MD5 functions */
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))

/* ROTATE_LEFT rotates x left n bits */
#if	defined(FAST_MD5) && defined(__GNUC__) && defined(mc68000)
/*
 * If we're on a 68000 based CPU and using a GNU C compiler with
 * inline assembly code, we can speed this up a bit.
 */
inline UINT4 ROTATE_LEFT(UINT4 x, int n)
{   
    asm("roll %2,%0" : "=d" (x) : "0" (x), "Ir" (n));
    return x;
}
#else
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
#endif


/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4 */
/* Rotation is separate from addition to prevent recomputation */
#define FF(a, b, c, d, x, s, ac)					\
	{(a) += F ((b), (c), (d)) + (x) + (UINT4)(ac);	\
		(a) = ROTATE_LEFT ((a), (s));				\
		(a) += (b);									\
	}
#define GG(a, b, c, d, x, s, ac)					\
	{(a) += G ((b), (c), (d)) + (x) + (UINT4)(ac);	\
		(a) = ROTATE_LEFT ((a), (s));				\
		(a) += (b);									\
	}
#define HH(a, b, c, d, x, s, ac)					\
	{(a) += H ((b), (c), (d)) + (x) + (UINT4)(ac);	\
		(a) = ROTATE_LEFT ((a), (s));				\
		(a) += (b);									\
	}
#define II(a, b, c, d, x, s, ac)					\
	{(a) += I ((b), (c), (d)) + (x) + (UINT4)(ac);	\
		(a) = ROTATE_LEFT ((a), (s));				\
		(a) += (b);									\
	}

/* The routine MD5Init initializes the message-digest context
   mdContext. All fields are set to zero.
*/
void MD5Init (mdContext)
	 MD5_CTX *mdContext;
{
	mdContext->i[0] = mdContext->i[1] = (UINT4)0;

	/* Load magic initialization constants.
	 */
	mdContext->buf[0] = (UINT4)0x67452301;
	mdContext->buf[1] = (UINT4)0xefcdab89;
	mdContext->buf[2] = (UINT4)0x98badcfe;
	mdContext->buf[3] = (UINT4)0x10325476;
}

/* The routine MD5Update updates the message-digest context to
   account for the presence of each of the characters inBuf[0..inLen-1]
   in the message whose digest is being computed.
*/
void MD5Update (mdContext, inBuf, inLen)
	 MD5_CTX *mdContext;
	 unsigned const char *inBuf;
	 unsigned int inLen;
{
	UINT4 in[16];
	int mdi;
	unsigned int i, ii;

	/* compute number of bytes mod 64 */
	mdi = (int)((mdContext->i[0] >> 3) & 0x3F);

	/* update number of bits */
	if ((mdContext->i[0] + ((UINT4)inLen << 3)) < mdContext->i[0])
		mdContext->i[1]++;
	mdContext->i[0] += ((UINT4)inLen << 3);
	mdContext->i[1] += ((UINT4)inLen >> 29);

	while (inLen--) {
		/* add new character to buffer, increment mdi */
		mdContext->in[mdi++] = *inBuf++;

		/* transform if necessary */
		if (mdi == 0x40) {
			for (i = 0, ii = 0; i < 16; i++, ii += 4)
				in[i] = (((UINT4)mdContext->in[ii+3]) << 24) |
					(((UINT4)mdContext->in[ii+2]) << 16) |
					(((UINT4)mdContext->in[ii+1]) << 8) |
					((UINT4)mdContext->in[ii]);
			Transform (mdContext->buf, in);
			mdi = 0;
		}
	}
}

/* The routine MD5Final terminates the message-digest computation and
   ends with the desired message digest in mdContext->digest[0...15].
*/

void MD5Final (mdContext)
	 MD5_CTX *mdContext;
{
	UINT4 in[16];
	int mdi;
	unsigned int i, ii;
	unsigned int padLen;

	/* save number of bits */
	in[14] = mdContext->i[0];
	in[15] = mdContext->i[1];

	/* compute number of bytes mod 64 */
	mdi = (int)((mdContext->i[0] >> 3) & 0x3F);

	/* pad out to 56 mod 64 */
	padLen = (mdi < 56) ? (56 - mdi) : (120 - mdi);
	MD5Update (mdContext, PADDING, padLen);

	/* append length in bits and transform */
	for (i = 0, ii = 0; i < 14; i++, ii += 4)
		in[i] = (((UINT4)mdContext->in[ii+3]) << 24) |
            (((UINT4)mdContext->in[ii+2]) << 16) |
            (((UINT4)mdContext->in[ii+1]) << 8) |
            ((UINT4)mdContext->in[ii]);
	Transform (mdContext->buf, in);

	/* store buffer in digest */
	for (i = 0, ii = 0; i < 4; i++, ii += 4) {
		mdContext->digest[ii] = (unsigned char)(mdContext->buf[i] & 0xFF);
		mdContext->digest[ii+1] =
			(unsigned char)((mdContext->buf[i] >> 8) & 0xFF);
		mdContext->digest[ii+2] =
			(unsigned char)((mdContext->buf[i] >> 16) & 0xFF);
		mdContext->digest[ii+3] =
			(unsigned char)((mdContext->buf[i] >> 24) & 0xFF);
	}
}

/* Basic MD5 step. Transforms buf based on in.
 */
static void Transform (buf, in)
	 UINT4 *buf;
	 UINT4 *in;
{
	UINT4 a = buf[0], b = buf[1], c = buf[2], d = buf[3];

	/* Round 1 */
#define S11 7
#define S12 12
#define S13 17
#define S14 22

	FF ( a, b, c, d, in[ 0], S11, 0xd76aa478); /* 1 */
	FF ( d, a, b, c, in[ 1], S12, 0xe8c7b756); /* 2 */
	FF ( c, d, a, b, in[ 2], S13, 0x242070db); /* 3 */
	FF ( b, c, d, a, in[ 3], S14, 0xc1bdceee); /* 4 */
	FF ( a, b, c, d, in[ 4], S11, 0xf57c0faf); /* 5 */
	FF ( d, a, b, c, in[ 5], S12, 0x4787c62a); /* 6 */
	FF ( c, d, a, b, in[ 6], S13, 0xa8304613); /* 7 */
	FF ( b, c, d, a, in[ 7], S14, 0xfd469501); /* 8 */
	FF ( a, b, c, d, in[ 8], S11, 0x698098d8); /* 9 */
	FF ( d, a, b, c, in[ 9], S12, 0x8b44f7af); /* 10 */
	FF ( c, d, a, b, in[10], S13, 0xffff5bb1); /* 11 */
	FF ( b, c, d, a, in[11], S14, 0x895cd7be); /* 12 */
	FF ( a, b, c, d, in[12], S11, 0x6b901122); /* 13 */
	FF ( d, a, b, c, in[13], S12, 0xfd987193); /* 14 */
	FF ( c, d, a, b, in[14], S13, 0xa679438e); /* 15 */
	FF ( b, c, d, a, in[15], S14, 0x49b40821); /* 16 */

	/* Round 2 */
#define S21 5
#define S22 9
#define S23 14
#define S24 20
	GG ( a, b, c, d, in[ 1], S21, 0xf61e2562); /* 17 */
	GG ( d, a, b, c, in[ 6], S22, 0xc040b340); /* 18 */
	GG ( c, d, a, b, in[11], S23, 0x265e5a51); /* 19 */
	GG ( b, c, d, a, in[ 0], S24, 0xe9b6c7aa); /* 20 */
	GG ( a, b, c, d, in[ 5], S21, 0xd62f105d); /* 21 */
	GG ( d, a, b, c, in[10], S22,  0x2441453); /* 22 */
	GG ( c, d, a, b, in[15], S23, 0xd8a1e681); /* 23 */
	GG ( b, c, d, a, in[ 4], S24, 0xe7d3fbc8); /* 24 */
	GG ( a, b, c, d, in[ 9], S21, 0x21e1cde6); /* 25 */
	GG ( d, a, b, c, in[14], S22, 0xc33707d6); /* 26 */
	GG ( c, d, a, b, in[ 3], S23, 0xf4d50d87); /* 27 */
	GG ( b, c, d, a, in[ 8], S24, 0x455a14ed); /* 28 */
	GG ( a, b, c, d, in[13], S21, 0xa9e3e905); /* 29 */
	GG ( d, a, b, c, in[ 2], S22, 0xfcefa3f8); /* 30 */
	GG ( c, d, a, b, in[ 7], S23, 0x676f02d9); /* 31 */
	GG ( b, c, d, a, in[12], S24, 0x8d2a4c8a); /* 32 */

	/* Round 3 */
#define S31 4
#define S32 11
#define S33 16
#define S34 23
	HH ( a, b, c, d, in[ 5], S31, 0xfffa3942); /* 33 */
	HH ( d, a, b, c, in[ 8], S32, 0x8771f681); /* 34 */
	HH ( c, d, a, b, in[11], S33, 0x6d9d6122); /* 35 */
	HH ( b, c, d, a, in[14], S34, 0xfde5380c); /* 36 */
	HH ( a, b, c, d, in[ 1], S31, 0xa4beea44); /* 37 */
	HH ( d, a, b, c, in[ 4], S32, 0x4bdecfa9); /* 38 */
	HH ( c, d, a, b, in[ 7], S33, 0xf6bb4b60); /* 39 */
	HH ( b, c, d, a, in[10], S34, 0xbebfbc70); /* 40 */
	HH ( a, b, c, d, in[13], S31, 0x289b7ec6); /* 41 */
	HH ( d, a, b, c, in[ 0], S32, 0xeaa127fa); /* 42 */
	HH ( c, d, a, b, in[ 3], S33, 0xd4ef3085); /* 43 */
	HH ( b, c, d, a, in[ 6], S34,  0x4881d05); /* 44 */
	HH ( a, b, c, d, in[ 9], S31, 0xd9d4d039); /* 45 */
	HH ( d, a, b, c, in[12], S32, 0xe6db99e5); /* 46 */
	HH ( c, d, a, b, in[15], S33, 0x1fa27cf8); /* 47 */
	HH ( b, c, d, a, in[ 2], S34, 0xc4ac5665); /* 48 */

	/* Round 4 */
#define S41 6
#define S42 10
#define S43 15
#define S44 21
	II ( a, b, c, d, in[ 0], S41, 0xf4292244); /* 49 */
	II ( d, a, b, c, in[ 7], S42, 0x432aff97); /* 50 */
	II ( c, d, a, b, in[14], S43, 0xab9423a7); /* 51 */
	II ( b, c, d, a, in[ 5], S44, 0xfc93a039); /* 52 */
	II ( a, b, c, d, in[12], S41, 0x655b59c3); /* 53 */
	II ( d, a, b, c, in[ 3], S42, 0x8f0ccc92); /* 54 */
	II ( c, d, a, b, in[10], S43, 0xffeff47d); /* 55 */
	II ( b, c, d, a, in[ 1], S44, 0x85845dd1); /* 56 */
	II ( a, b, c, d, in[ 8], S41, 0x6fa87e4f); /* 57 */
	II ( d, a, b, c, in[15], S42, 0xfe2ce6e0); /* 58 */
	II ( c, d, a, b, in[ 6], S43, 0xa3014314); /* 59 */
	II ( b, c, d, a, in[13], S44, 0x4e0811a1); /* 60 */
	II ( a, b, c, d, in[ 4], S41, 0xf7537e82); /* 61 */
	II ( d, a, b, c, in[11], S42, 0xbd3af235); /* 62 */
	II ( c, d, a, b, in[ 2], S43, 0x2ad7d2bb); /* 63 */
	II ( b, c, d, a, in[ 9], S44, 0xeb86d391); /* 64 */

	buf[0] += a;
	buf[1] += b;
	buf[2] += c;
	buf[3] += d;
}

/*
***********************************************************************
** End of md5.c                                                      **
******************************** (cut) ********************************
*/
